ELECTROPLATING AND THE PREVENTION OF RUST. Rebecca Xu and Anna Olson.

The aim of this work is to determine what affect the variable of time has on the process of electroplating. This work examines the oxidation-reduction mechanisms behind electroplating and explores how plated metals can help prevent rust and corrosion. Four trials at 30 second, 1 minute, 3 minutes and 5 minutes intervals were performed in this experiment. The copper cathode and zinc anode were submerged in a 0.5 M zinc sulfate solution and a current was applied to initiate the electrodeposition. It was determined that the five minute electroplating trial yielded the thickest zinc coating on the copper cathode, as it increased in mass by 0.063 grams. The findings of this experiment may be applied to the industrial electroplating process, especially in the prevention of rust.
Key words: electroplating, oxidation-reduction, rust, corrosion, cathode, anode, electrodeposition


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Figure 1: .5 M ZnSO4 solution, copper strip, zinc strip, positive and negative terminals
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Figure 2: 1 minute, 3 minute, and 5 minute trials for electroplated and rusted copper strips

Results
Data
Part 1: Electroplating copper and zinc
Time
Copper starting mass
Copper end mass
Zinc starting mass
Zinc end mass
30 seconds
.663 grams
.675 grams
.582 grams
.578 grams
1 minute
.691 grams
.703 grams
.590 grams
.589 grams
3 minutes
.679 grams
.703 grams
.568 grams
.551 grams
5 minutes
.685 grams
.748 grams
.583 grams
.538 grams

Table 1: Starting and end masses of copper and zinc strips after electroplating

Time
Physical Description
30 seconds
Copper plates 3 seconds into experiment. The submerged part of copper turns dark grey instantly while the submerged part of Zinc turns light grey. Crystals barely begin to form.
1 minute
Copper plates immediately, turning dark grey. Zinc turns light silver/white. Copper begins to form a thin layer of crystals 7 seconds into experiment.
3 minutes
Copper plates 8 seconds into experiment. Bubbles form around the submerged copper strip after 20 seconds. After 1 minute and 10 seconds, a thick layer of crystals covers the submerged copper strip.
5 minutes
Copper plates very quickly. A dense layer of crystals form over the copper strip after 1 minute. The crystals begin from the edges and works toward the middle part of the copper strip.

Table 2: Physical description of electroplating copper and zinc

Part 2: Preventing Rust

Time
Mass after sitting in water
30 seconds
.684 grams
1 minute
.718 grams
3 minutes
.722 grams
5 minutes
.737 grams

Table 3: Masses of copper after sitting in water for 24 hours



Works Consulted

Bazant, M.Z., Chu, K.T., & Bayly, B.J. (2005). Current-voltage relations for electrochemical thin films.
Society for Industrial and Applied Mathematics, 65(5), Retrieved from http://www.jstor.org/stable/4096138Search=yes&searchUri=%2Faction%2FdoBasic
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2Banode%26Search%3DSearch%26hp%3D25%26wc%3Don


Hoar, T.P. (1976). Review lecture: corrosion of metals: its cost and control. Proceedings of the
Royal Society of London. Series A, Mathematical and Physical Sciences, 348(1652), Retrieved from http://www.jstor.org/stable/79113